The dramatic reduction in HIV/AIDS-related deaths in developed nations is due in part to the use of antiretroviral therapy (ART). The initiation and monitoring of ART are guided by algorithms that combine clinical symptoms, CD4 lymphocyte count, and HIV viral load. While access to ART has recently increased and the World Health Organization has issued guidelines for HIV treatment in resource-limited settings, few studies have evaluated effectiveness of ART and sustainable methods to guide treatment decisions in these settings. We propose to conduct a cross-sectional, pilot study followed by an observational, prospective study of HIV infected patients in Kampala, Uganda. The research will assess response to ART and evaluate alternative, inexpensive methods to monitor this response. Our hypothesis is that clinical findings combined with inexpensive laboratory tests can be used to guide HIV care. The specific aims of this project are 1) to measure clinical, virologic and immunologic responses to the initiation of ART in HIV infected patients in Uganda and 2) to evaluate the role of alternative, inexpensive laboratory methods compared to gold standard assays for monitoring CD4 lymphocyte count and HIV viral load. This proposal builds directly on our prior work that shows an increase in sensitivity by using hemoglobin in addition to total lymphocyte count to predict CD4 lymphocyte count. The proposed research lays the foundation for the development of clinical algorithms that allow practitioners in resource-limited settings to initiate and monitor ART with basic laboratory and diagnostic facilities. There is an urgent need to establish clinical practices and algorithms that require minimal technical and personnel resources. My career development plan includes advanced coursework at the Johns Hopkins Bloomberg School of Public Health and structured mentoring in HIV clinical epidemiology with Dr. Richard Moore and HIV laboratory science with Dr. Thomas Quinn. My long-term goal is to become an independent investigator of HIV clinical epidemiology in resource-limited settings.